What is this white streak?! CCD issue? lense problem? noise?

[BlackHoleSunGod]

Hiya Everybody!

I'm very green to photography but getting into the swing of it, so please... be gentle.

I own a Toshiba PDR-M700 which is a decent point & shoot and "starter" camera while I practice before getting a D-SLR

Before getting into it, I will mention my camera has been serviced/repaired. There was an LCD issue that had to be corrected.

Anyhow... I noticed this white "streak" in my night photos I've been taking over the last year & thought it was from moonlight or something, butthe other night I took some photos & noticed it quite easily. I've no idea what it *actually* is or what this would be called, was hopeing someone might have an idea.

It looks like a white smear / streak that goes down the left side, dominantly in the upper left though... along w/ the images I'll include the settings that the image meta data captures if it helps.


ISO 100, 16s, f8


ISO 100, 10s, f8

These images were taken in opposite directions of each other. Cloudy, no overhead lighting, etc.
I've no idea if the white streak is related to the servicing or not, or if its a setting issue... just trying to figure it out so I can take corrective action.

Thank you in advance for any assistance,
BHSG

[another view]

I had to click on the image, then the image in that window to get it big enough to see what you were talking about. Honestly, I don't think it's too bad and it could be easily and quickly cloned out in Photoshop.

Strange things happen with digicams and long exposures. I have an older Coolpix 5000, and it starts showing hot pixels and bad noise at less than one second. This looks great by comparison. Does this also show up at faster shutter speeds, like 1/125?

[BlackHoleSunGod]

I had to click on the image, then the image in that window to get it big enough to see what you were talking about. Honestly, I don't think it's too bad and it could be easily and quickly cloned out in Photoshop.

Strange things happen with digicams and long exposures. I have an older Coolpix 5000, and it starts showing hot pixels and bad noise at less than one second. This looks great by comparison. Does this also show up at faster shutter speeds, like 1/125?

Yeah, I'm sorry about the "multiple clicking" to get a proper image size... thats due in part to Imageshack, only place I knew I could hoss the images for free.

hrm... do you mean taking a night image @ less than one second? I know sunlight images are fine, it appears to be the long exposure ones that show this. I'll give your suggestion a try & report back.

Thanks for the reply!

[SmartWombat]

Are you talking about the streaky lighter patch in the top left corner of the first image?
And the lines up the left hand side of the second image?

That looks like noise from the sensor readout amplifiers.
It could be just an electronic problem.
You'd notice it in daylight photos if it was a light leak.

[another view]

Even one second might give you a problem but there's going to be a point at which it can be seen (because daylight shots are OK). Like I say, a few seconds will clone out at least these shots in Photoshop.

FWIW, photobucket.com is a good free hosting site.

[BlackHoleSunGod]

Are you talking about the streaky lighter patch in the top left corner of the first image?
And the lines up the left hand side of the second image?

That looks like noise from the sensor readout amplifiers.
It could be just an electronic problem.
You'd notice it in daylight photos if it was a light leak.

Yes!
That is exactly it, the streaky patches & the lines. I'd say I can spot it in about 90% of the night photos I've taken over the last year.
And so far its only noticible at night.


hrm... so if it's an electronic issue... and it's not suppsoed to do that... it gets to be serviced. Again.
Lucky me.

[another view]

I don't know if it's really a matter of needing to be serviced - it may just be a matter of using the camera beyond it's capabilities. DSLR's are much better at low light, part of the reason may be the larger sensor but a DSLR will make a big difference in shots like this.

[SmartWombat]

It may just be inherent in the sensor.
On really long exposures you can get a kind of glow around the amplifiers.
I assume that's heat, because the sensor responts to Infra Red.

http://www.astrosurf.org/buil/20d/20dvs10d.htm


See the 10d has marks remarkably like yours


Yet the 20D does not suffer as badly.



Another article says the 1DmkII turns off the amplifiers during log exposures and has no glow in astrophotography.

Also a good reply on an astrophotography thread "You're right, it is amplifier noise. This is a known problem on CCD sensors, but not on CMOS sensors (as Canon uses). However; it can be solved by turning the internal long shutter noise reduction on. I'm not planning on doing astrophotography anyway, I just wondered if it was my camera or a genereal problem."

That seems not to be true, as I also found a 300D image showing amplifier glow.

This article http://cobalt.golden.net/~kwastro/im...ummer_2005.pdf talks about fixing problems with software. But that light frame/darl frame calibration is really only suitable for astronomers


SO it may just be a built-in limitation of the camera.
Has it always done it?
Or do you have old photos that don't show this?

[BlackHoleSunGod]

SmartWombat... you are awesome. I'd just like to start by saying that. Your post makes complete sense to me.

I have photos that don't show it, but they are not long explosure... I really didnt learn "how to" take those until this year, after I had it initially serviced, so I don't have any pre-service long exposure photos to compare it to.

I do think you've hit the nail on the head though.
...Guess I'll just deal with it (and scrimp & save my pennies) until I get a DSLR.

And thank you Another View for your input as well! I put this on a few other photo forums, this has been the most helpful so far.